Going back to your vehicle analagy. Sure, you and your wife can probably handle it. The boat is mechanised and automated in such a way to allow it to be operated short handed.
Just like a 45' motorhome can be driven down the I-90 by a retired couple in great comfort. But what you don't want to do with that motor home is take it on a back road and get it stuck in a mud hole, or have a flat tire in a place where AAA offers no service, or slide it off the road in a snow storm or park it in little Italy in Boston on a Saturday night.
Buy what ever toy you like, but do it with eyes wide open recognising the conveyances limitations.
Hey, I grew up just south of Boston and my family name is Scavongelli, what are you trying to say???
The best boat for world cruising will likely have some limitations when it comes to gunkholing. We always look for the best compromise for what we intend to do the largest portion of the time.
We want a big cockpit because we will spend most of our time there. We want interior space because it will be our apartment for a few years. We want a separate room for the 'wine cellar'. We want space for the golf clubs, dive compressor and gear, ice maker, etc...
Back to the OP's original question: Yes, I think most people consider the things you are asking. I do not know why there is not more discussion about it.
We know what we (think) we want. There are needs, wants, and nice to haves. We have made lists and prioritized. We will consider what is out there at what price and make an informed decision when it is time to pull the trigger (01/01/2020).